Add --enable-solaris to descend into solaris-specific build directory.

While it doesn't take a long time to build, this is currently the only
thing in the tree that doesn't work with BSD make, and there's no
reason to build solaris package control files on other systems.

Makefile.am

@@ -2,7 +2,7 @@
 
 SUBDIRS = lib @ZEBRA@ @BGPD@ @RIPD@ @RIPNGD@ @OSPFD@ @OSPF6D@ \
          @ISISD@ @WATCHQUAGGA@ @VTYSH@ @OSPFCLIENT@ doc m4 @pkgsrcdir@ \
-         redhat solaris
+         redhat @SOLARIS@
 
 DIST_SUBDIRS = lib zebra bgpd ripd ripngd ospfd ospf6d \
 	  isisd watchquagga vtysh ospfclient doc m4 pkgsrc redhat tests \

configure.ac

@@ -197,6 +197,8 @@ AC_ARG_ENABLE(watchquagga,
 [  --disable-watchquagga   do not build watchquagga])
 AC_ARG_ENABLE(isisd,
 [  --enable-isisd          build isisd])
+AC_ARG_ENABLE(solaris,
+[  --enable-solaris          build solaris])
 AC_ARG_ENABLE(bgp-announce,
 [  --disable-bgp-announce, turn off BGP route announcement])
 AC_ARG_ENABLE(netlink,
@@ -1131,6 +1133,13 @@ case "${enable_isisd}" in
   *    ) ;;
 esac
 
+# XXX Perhaps auto-enable on Solaris, but that's messy for cross builds.
+case "${enable_solaris}" in
+  "yes") SOLARIS="solaris";;
+  "no" ) SOLARIS="";;
+  *    ) ;;
+esac
+
 if test "${enable_bgp_announce}" = "no";then
   AC_DEFINE(DISABLE_BGP_ANNOUNCE,,Disable BGP installation to zebra)
 fi
@@ -1143,6 +1152,7 @@ AC_SUBST(OSPFD)
 AC_SUBST(OSPF6D)
 AC_SUBST(WATCHQUAGGA)
 AC_SUBST(ISISD)
+AC_SUBST(SOLARIS)
 AC_SUBST(VTYSH)
 AC_SUBST(INCLUDES)
 AC_SUBST(CURSES)